My 2005 6MT needs both front and rear O2 sensors. Research on the net showed that Mazda quotes 2 different part numbers (with significantly different prices ; eg $304-front, $129-rear).

I have found several aftermarket dealers offering replacement 4 -wire sensors (NGK) which are identical for both the front and rear. The price quoted is much less than the original Mazda parts.

(sample site - http://www.sparkplugs.com/results_app.asp).

Does anyone know if these sensors will work with no cutting or other mods, and why are they identical when Mazda uses 2 different sensors?

 

The front sensor is a wideband sensor and the rear sensor is a narrowband sensor. They aren't the same and the front is more expensive.

You should be able to get better pricing though.

Can't see the sensors on your link.

 

Thanks for the info. Here is another site which claims that this sensor will work for both front and rear (and costs only $122.39).

I think I'll play it safe and go with the Mazda original.

 

^yeah i'd prob go with mazda parts too...just to be safe...